Multi-output laser-radiation source

Abstract

A laser-radiation source includes a laser delivering an output beam, a lens, and an optical arrangement for dividing the output beam into a main beam and an auxiliary beam. The main and auxiliary beams are coupled by the lens into entrance faces of respectively a main optical fiber and an auxiliary optical fiber. The entrance face of the main optical fiber is located on the optical axis of the lens. The entrance face of the auxiliary optical fiber is laterally displaced from the optical axis of the lens.

What is claimed is:  
     
       1. Optical apparatus, comprising: 
       a laser delivering a first laser-radiation beam;  
       a lens having an optical axis;  
       first and second optical fibers, each thereof having an entrance face, with the entrance face of the first optical fiber being substantially aligned with the optical axis of the lens and the entrance face of the second optical fiber being spaced therefrom; and  
       an optical arrangement for dividing said first laser-radiation beam into second and third laser-radiation beams, said second laser radiation beam being directed into the lens substantially along the optical axis thereof and the third laser radiation beam being directed into the lens at an angle with respect to the optical axis thereof, said laser second and third laser-radiation beams being coupled by said lens into respectively said first and second optical fibers via said entrance faces thereof.  
     
     
       2. The apparatus of  claim 1 , wherein said beam-dividing arrangement is located between said laser and said lens. 
     
     
       3. The apparatus of  claim 2 , wherein the entrance face of the first optical fiber is spaced apart from said lens on a side thereof opposite said beam-dividing arrangement. 
     
     
       4. The apparatus of  claim 3 , wherein the entrance face of said second optical fiber is spaced apart from said lens by about the same distance as said entrance face of said first optical fiber. 
     
     
       5. The apparatus of  claim 4 , wherein said entrance faces of said optical fibers are spaced apart from said lens by about one focal-length of said lens. 
     
     
       6. The apparatus of  claim 1 , wherein said optical beam-dividing arrangement is a wedge of a transparent material having first and second surfaces located in the path of said first laser-radiation beam, said first and second surfaces being numbered in the direction of propagation of said laser-radiation beam. 
     
     
       7. The apparatus of  claim 6 , wherein said first laser-radiation beam is transmitted through said first surface of said wedge such that it is incident on said second surface thereof, a first portion of said transmitted first laser-radiation-beam being transmitted through said second surface of said wedge to provide said second laser-radiation beam, and wherein a second portion of said first laser-radiation beam is reflected from said second surface of said wedge, and a portion of said first-surface-reflected portion is reflected from said first surface of said wedge and transmitted through said second surface of said wedge to provide said third laser-radiation beam. 
     
     
       8. The apparatus of  claim 7 , wherein said second laser-radiation beam, on exiting said wedge, propagates generally along said optical axis of said lens, and said third laser-radiation beam propagates at an angle to said optical axis of said lens. 
     
     
       9. The apparatus of  claim 8 , wherein said second and third laser beams are parallel to each other on exiting said lens. 
     
     
       10. The apparatus of  claim 1 , wherein said optical beam-dividing arrangement includes a plate of a transparent material and a mirror, said plate being located on said optical axis of said lens and inclined thereto, said plate and said mirror being arranged such that a portion of said first laser-radiation beam is transmitted through said plate to provide said second laser-radiation beam, and a second portion of said first laser-radiation beam is reflected from a surface of said plate onto said mirror and reflected from said mirror through said plate to provide said third laser-radiation beam. 
     
     
       11. The apparatus of  claim 10 , wherein said second laser-radiation beam, on exiting said plate, propagates generally along said optical axis of said lens, and said third laser beam, on exiting said plate, propagates at an angle to said optic axis of said lens. 
     
     
       12. Optical apparatus, comprising: 
       a laser delivering a first laser-radiation beam;  
       first and second optical fibers, each thereof having an entrance face;  
       an optical wedge of a transparent material having first and second surfaces located in the path of said first laser-radiation beam, said optical wedge being arranged to divide said first laser-radiation beam into second and third laser-radiation beams; and  
       a lens having an optical axis, said lens arranged to couple said second and third laser-radiation beams into respectively said first and second optical fibers via said entrance faces thereof with the entrance face of the first optical fiber being substantially aligned with the optical axis of the lens and the entrance face of the second optical fiber being spaced therefrom and wherein said second laser radiation beam is directed by said wedge into the lens substantially along the optical axis thereof and wherein the third laser radiation beam is directed by said wedge into the lens at an angle with respect to the optical axis thereof.  
     
     
       13. The apparatus of  claim 12 , wherein said optical wedge is located between said laser and said lens. 
     
     
       14. The apparatus of  claim 13 , wherein the entrance face of the first optical fiber is spaced apart from said lens on a side thereof opposite said optical wedge. 
     
     
       15. The apparatus of  claim 14 , wherein the entrance face said second optical fiber is spaced apart from said lens by about the same distance as said entrance face of said first optical fiber. 
     
     
       16. The apparatus of  claim 15 , wherein said entrance faces of said optical fibers are spaced apart from said lens by about one focal length of said lens. 
     
     
       17. Optical apparatus, comprising: 
       a laser delivering a laser-radiation beam;  
       a lens having an optical axis;  
       first and second optical fibers each thereof having an entrance face;  
       a transparent plate located on said optical axis of said lens and inclined thereto, said plate transmitting a first portion of said laser-radiation beam along the optical axis of the lens, and wherein a second portion of said laser-radiation beam is reflected from a surface of said plate  
       a mirror positioned to reflect said second portion back through the plate so that the second portion enters the lens at an angle with respect to the optical axis thereof; and  
       said lens being arranged to couple said first and second beam portions into respectively said first and second optical fibers via said entrance faces thereof with the entrance face of the first optical fiber being substantially aligned with the optical axis of the lens and the entrance face of the second optical fiber being spaced therefrom.  
     
     
       18. The apparatus of  claim 17 , wherein the entrance face of the first optical fiber spaced apart from said lens on a side thereof opposite said transparent plate. 
     
     
       19. The apparatus of  claim 18 , wherein the entrance face of said second optical fiber is spaced apart from said lens by about the same distance as said entrance face of said first optical fiber. 
     
     
       20. The apparatus of  claim 19 , wherein said entrance faces of said optical fibers are spaced apart from said lens by about one focal length of said lens. 
     
     
       21. In a laser delivery system, wherein the output beam from a laser is focused into a main delivery fiber by a lens and wherein the entrance face of the delivery fiber is substantially aligned with the optical axis of the lens, an arrangement for monitoring the power of the beam coupled into the main delivery fiber comprising: 
       a secondary delivery fiber having an entrance face near the entrance face of the main delivery fiber; and  
       an optical beam divider located between the laser and the focusing lens, said beam divider for splitting the beam into a primary beam portion and a secondary beam portion, with the energy of the primary beam portion being at least about an order of magnitude greater than the secondary beam portion, said beam divider being configured so that the primary beam portion is directed into the lens along the optical axis thereof and focused by the lens into the entrance face of the main delivery fiber and wherein the secondary beam portion is directed into the lens at an angle with respect to and spaced from the primary beam portion such that the secondary beam portion is focused into the entrance face of the secondary delivery fiber, wherein the laser energy carried by the secondary delivery fiber can be monitored to provide information about the energy carried by the main delivery fiber.  
     
     
       22. A delivery system as recited in  claim 21 , wherein said beam divider is defined by a wedge of transparent material. 
     
     
       23. A delivery system as recited in  claim 21 , wherein said beam divider is defined by a combination of a transparent plate and mirror, wherein the transparent plate is inclined at an angle with respect to the propagation axis of the beam. 
     
     
       24. The delivery system of  claim 21 , wherein said entrance faces of said optical fibers are spaced apart from said lens by about one focal-length of said lens. 
     
     
       25. The delivery system of  claim 21 , wherein the propagation axes of said primary and secondary beam portions are parallel to each other on exiting said lens.